P-Glycoprotein-Activity Measurements in Multidrug Resistant Cell Lines: Single-Cell versus Single-Well Population Fluorescence Methods

Table 1

Intermethods comparison of fluorescence increase detection thresholds.

	MCF-7		Hs578T
	0,1 µM VRP	0,1 µM PSC833	0,1 µM VRP	0,1 µM PSC833
Flow cytometer
Mean FL1	**	***	*	***
Mean FL1-FC	**	***	*	**
Microplate reader
Well fluorescence	***	*	**	**
Single cell fluorescence	***	***	**	**

Flow cytometer (mean FL1 and mean FL1-FC) and microplate reader (whole well fluorescence and mean single cell fluorescence) signal increase detection thresholds were estimated by testing groups of untreated cells and cells treated with the lowest P-gp antagonists concentration (0,1 µM) for significant differences (*P < 0,05; **P < 0,01; ***P < 0,001; paired Student’s t-test; 𝑛=10).